Identify the number that breaks the arithmetic progression.
30, 40, 50, 61, 70
Show answer & explanation
Correct answer: B
Explanation
40 − 30 = 10
50 − 40 = 10
61 − 50 = 11
70 − 61 = 9
Clearly, the series should increase by a difference of 10:
30, 40, 50, 60, 70
So 61 is the wrong number.
Correct answer: (b) 61